The disclosure relates in general to a biosignal intensity detecting method, a bedding state judging method, and a bedding state monitoring device. The methods and monitoring device are used to detect whether a target person is in or out of bed or bedclothes and whether the intensity level of biosignals from the person in bed is decreasing.
An elderly person, a person who requires care, or an inpatient is under the care of his or her family members, a nursing care worker, or a nurse in a hospital or a medical institution who must pay constant attention to the condition of their patient or elderly person but cannot be in attendance all the time.
For example, when a family lives with an elderly person who requires care, someone in the family must go to the elderly person's room frequently to check the condition or behavior of the elderly person. In a nursing-care institution or hospital, patrolling at night on a regular basis is required for checking the condition of a patient during nighttime. But under present circumstances it is difficult to find people to spare for patrolling. Additionally, in the case where an accident happens to a patient, there is no other way for the patient but to use a buzzer attached to a bed to contact hospital personnel. The buzzer is useless if the patient is in no condition to operate the buzzer. An elderly person living alone is at an even greater disadvantage. The elderly person has no attendants to take care of him or her, so others cannot know about his or her condition.
If an elderly person or patient in bed has an abnormality in his or her body and is left alone for a long time, he or she may be placed in a fatal condition. Hence a monitoring device, capable of constantly monitoring the condition and daily behavior of a patient, has been in great demand.
It is desirable to monitor the condition of a patient without imposing any mental or physical burden on the patient. For this reason, a device for noninvasive monitoring is imperative for monitoring the patient.
The inventor has proposed a novel method disclosed in Japanese Published Unexamined Patent Application No. H11-19056. According to the method, an air mat is laid under a subject and a minute differential pressure sensor for detecting the inner pressure of the mat is used to detect vibrations caused by the heartbeat of the subject in a noninvasive manner. The vibrations are processed as signals, which are detected as heartbeat signals or respiratory signals.
The inventor has also proposed an apparatus disclosed in Japanese Published Unexamined Patent Application No. 2002-58653. According to the apparatus, an air tube is laid under a subject and a minute differential pressure sensor for detecting the inner pressure of the air tube is used to detect vibrations caused by the heartbeat of the subject in a noninvasive manner. The vibrations are processed as signals, which are detected as heartbeat signals or respiratory signals.
In addition, a method for judging whether a person is in bed is disclosed in Japanese Published Unexamined Patent Application No. H5-192315. According to the method, an air mat is laid under the bed or bedclothes, and a pressure change of the air mat caused by the person's body motion, tossing, etc., is detected to make a judgment whether a person is in or out of bed.
The method disclosed in Japanese Published Unexamined Patent Application No. H5-192315 allows a monitoring person to know whether the subject is in or out of bed, but does not allow the monitoring person to know the condition or daily behavior of the subject.